/*
 * GPIO driver for Marvell SoCs
 *
 * Copyright (C) 2012 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 * Andrew Lunn <andrew@lunn.ch>
 * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2.  This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 *
 * This driver is a fairly straightforward GPIO driver for the
 * complete family of Marvell EBU SoC platforms (Orion, Dove,
 * Kirkwood, Discovery, Armada 370/XP). The only complexity of this
 * driver is the different register layout that exists between the
 * non-SMP platforms (Orion, Dove, Kirkwood, Armada 370) and the SMP
 * platforms (MV78200 from the Discovery family and the Armada
 * XP). Therefore, this driver handles three variants of the GPIO
 * block:
 * - the basic variant, called "orion-gpio", with the simplest
 *   register set. Used on Orion, Dove, Kirkwoord, Armada 370 and
 *   non-SMP Discovery systems
 * - the mv78200 variant for MV78200 Discovery systems. This variant
 *   turns the edge mask and level mask registers into CPU0 edge
 *   mask/level mask registers, and adds CPU1 edge mask/level mask
 *   registers.
 * - the armadaxp variant for Armada XP systems. This variant keeps
 *   the normal cause/edge mask/level mask registers when the global
 *   interrupts are used, but adds per-CPU cause/edge mask/level mask
 *   registers n a separate memory area for the per-CPU GPIO
 *   interrupts.
 */

#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/machine.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/mfd/syscon.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/slab.h>

/*
 * GPIO unit register offsets.
 */
#define GPIO_OUT_OFF                    0x0000
#define GPIO_IO_CONF_OFF                0x0004
#define GPIO_BLINK_EN_OFF               0x0008
#define GPIO_IN_POL_OFF                 0x000c
#define GPIO_DATA_IN_OFF                0x0010
#define GPIO_EDGE_CAUSE_OFF             0x0014
#define GPIO_EDGE_MASK_OFF              0x0018
#define GPIO_LEVEL_MASK_OFF             0x001c
#define GPIO_BLINK_CNT_SELECT_OFF       0x0020

/*
 * PWM register offsets.
 */
#define PWM_BLINK_ON_DURATION_OFF       0x0
#define PWM_BLINK_OFF_DURATION_OFF      0x4
#define PWM_BLINK_COUNTER_B_OFF         0x8

/* Armada 8k variant gpios register offsets */
#define AP80X_GPIO0_OFF_A8K             0x1040
#define CP11X_GPIO0_OFF_A8K             0x100
#define CP11X_GPIO1_OFF_A8K             0x140

/* The MV78200 has per-CPU registers for edge mask and level mask */
#define GPIO_EDGE_MASK_MV78200_OFF(cpu)   ((cpu) ? 0x30 : 0x18)
#define GPIO_LEVEL_MASK_MV78200_OFF(cpu)  ((cpu) ? 0x34 : 0x1C)

/*
 * The Armada XP has per-CPU registers for interrupt cause, interrupt
 * mask and interrupt level mask. Those are in percpu_regs range.
 */
#define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
#define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu)  (0x10 + (cpu) * 0x4)
#define GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu) (0x20 + (cpu) * 0x4)

#define MVEBU_GPIO_SOC_VARIANT_ORION    0x1
#define MVEBU_GPIO_SOC_VARIANT_MV78200  0x2
#define MVEBU_GPIO_SOC_VARIANT_ARMADAXP 0x3
#define MVEBU_GPIO_SOC_VARIANT_A8K      0x4

#define MVEBU_MAX_GPIO_PER_BANK         32

struct mvebu_pwm {
        struct regmap           *regs;
        u32                      offset;
        unsigned long            clk_rate;
        struct gpio_desc        *gpiod;
        struct pwm_chip          chip;
        spinlock_t               lock;
        struct mvebu_gpio_chip  *mvchip;

        /* Used to preserve GPIO/PWM registers across suspend/resume */
        u32                      blink_select;
        u32                      blink_on_duration;
        u32                      blink_off_duration;
};

struct mvebu_gpio_chip {
        struct gpio_chip   chip;
        struct regmap     *regs;
        u32                offset;
        struct regmap     *percpu_regs;
        int                irqbase;
        struct irq_domain *domain;
        int                soc_variant;

        /* Used for PWM support */
        struct clk        *clk;
        struct mvebu_pwm  *mvpwm;

        /* Used to preserve GPIO registers across suspend/resume */
        u32                out_reg;
        u32                io_conf_reg;
        u32                blink_en_reg;
        u32                in_pol_reg;
        u32                edge_mask_regs[4];
        u32                level_mask_regs[4];
};

/*
 * Functions returning addresses of individual registers for a given
 * GPIO controller.
 */

static void mvebu_gpioreg_edge_cause(struct mvebu_gpio_chip *mvchip,
                         struct regmap **map, unsigned int *offset)
{
        int cpu;

        switch (mvchip->soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                *map = mvchip->regs;
                *offset = GPIO_EDGE_CAUSE_OFF + mvchip->offset;
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                cpu = smp_processor_id();
                *map = mvchip->percpu_regs;
                *offset = GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu);
                break;
        default:
                BUG();
        }
}

static u32
mvebu_gpio_read_edge_cause(struct mvebu_gpio_chip *mvchip)
{
        struct regmap *map;
        unsigned int offset;
        u32 val;

        mvebu_gpioreg_edge_cause(mvchip, &map, &offset);
        regmap_read(map, offset, &val);

        return val;
}

static void
mvebu_gpio_write_edge_cause(struct mvebu_gpio_chip *mvchip, u32 val)
{
        struct regmap *map;
        unsigned int offset;

        mvebu_gpioreg_edge_cause(mvchip, &map, &offset);
        regmap_write(map, offset, val);
}

static inline void
mvebu_gpioreg_edge_mask(struct mvebu_gpio_chip *mvchip,
                        struct regmap **map, unsigned int *offset)
{
        int cpu;

        switch (mvchip->soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                *map = mvchip->regs;
                *offset = GPIO_EDGE_MASK_OFF + mvchip->offset;
                break;
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
                cpu = smp_processor_id();
                *map = mvchip->regs;
                *offset = GPIO_EDGE_MASK_MV78200_OFF(cpu);
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                cpu = smp_processor_id();
                *map = mvchip->percpu_regs;
                *offset = GPIO_EDGE_MASK_ARMADAXP_OFF(cpu);
                break;
        default:
                BUG();
        }
}

static u32
mvebu_gpio_read_edge_mask(struct mvebu_gpio_chip *mvchip)
{
        struct regmap *map;
        unsigned int offset;
        u32 val;

        mvebu_gpioreg_edge_mask(mvchip, &map, &offset);
        regmap_read(map, offset, &val);

        return val;
}

static void
mvebu_gpio_write_edge_mask(struct mvebu_gpio_chip *mvchip, u32 val)
{
        struct regmap *map;
        unsigned int offset;

        mvebu_gpioreg_edge_mask(mvchip, &map, &offset);
        regmap_write(map, offset, val);
}

static void
mvebu_gpioreg_level_mask(struct mvebu_gpio_chip *mvchip,
                         struct regmap **map, unsigned int *offset)
{
        int cpu;

        switch (mvchip->soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                *map = mvchip->regs;
                *offset = GPIO_LEVEL_MASK_OFF + mvchip->offset;
                break;
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
                cpu = smp_processor_id();
                *map = mvchip->regs;
                *offset = GPIO_LEVEL_MASK_MV78200_OFF(cpu);
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                cpu = smp_processor_id();
                *map = mvchip->percpu_regs;
                *offset = GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu);
                break;
        default:
                BUG();
        }
}

static u32
mvebu_gpio_read_level_mask(struct mvebu_gpio_chip *mvchip)
{
        struct regmap *map;
        unsigned int offset;
        u32 val;

        mvebu_gpioreg_level_mask(mvchip, &map, &offset);
        regmap_read(map, offset, &val);

        return val;
}

static void
mvebu_gpio_write_level_mask(struct mvebu_gpio_chip *mvchip, u32 val)
{
        struct regmap *map;
        unsigned int offset;

        mvebu_gpioreg_level_mask(mvchip, &map, &offset);
        regmap_write(map, offset, val);
}

/*
 * Functions returning offsets of individual registers for a given
 * PWM controller.
 */
static unsigned int mvebu_pwmreg_blink_on_duration(struct mvebu_pwm *mvpwm)
{
        return mvpwm->offset + PWM_BLINK_ON_DURATION_OFF;
}

static unsigned int mvebu_pwmreg_blink_off_duration(struct mvebu_pwm *mvpwm)
{
        return mvpwm->offset + PWM_BLINK_OFF_DURATION_OFF;
}

/*
 * Functions implementing the gpio_chip methods
 */
static void mvebu_gpio_set(struct gpio_chip *chip, unsigned int pin, int value)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);

        regmap_update_bits(mvchip->regs, GPIO_OUT_OFF + mvchip->offset,
                           BIT(pin), value ? BIT(pin) : 0);
}

static int mvebu_gpio_get(struct gpio_chip *chip, unsigned int pin)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
        u32 u;

        regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset, &u);

        if (u & BIT(pin)) {
                u32 data_in, in_pol;

                regmap_read(mvchip->regs, GPIO_DATA_IN_OFF + mvchip->offset,
                            &data_in);
                regmap_read(mvchip->regs, GPIO_IN_POL_OFF + mvchip->offset,
                            &in_pol);
                u = data_in ^ in_pol;
        } else {
                regmap_read(mvchip->regs, GPIO_OUT_OFF + mvchip->offset, &u);
        }

        return (u >> pin) & 1;
}

static void mvebu_gpio_blink(struct gpio_chip *chip, unsigned int pin,
                             int value)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);

        regmap_update_bits(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset,
                           BIT(pin), value ? BIT(pin) : 0);
}

static int mvebu_gpio_direction_input(struct gpio_chip *chip, unsigned int pin)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
        int ret;

        /*
         * Check with the pinctrl driver whether this pin is usable as
         * an input GPIO
         */
        ret = pinctrl_gpio_direction_input(chip->base + pin);
        if (ret)
                return ret;

        regmap_update_bits(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset,
                           BIT(pin), BIT(pin));

        return 0;
}

static int mvebu_gpio_direction_output(struct gpio_chip *chip, unsigned int pin,
                                       int value)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
        int ret;

        /*
         * Check with the pinctrl driver whether this pin is usable as
         * an output GPIO
         */
        ret = pinctrl_gpio_direction_output(chip->base + pin);
        if (ret)
                return ret;

        mvebu_gpio_blink(chip, pin, 0);
        mvebu_gpio_set(chip, pin, value);

        regmap_update_bits(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset,
                           BIT(pin), 0);

        return 0;
}

static int mvebu_gpio_get_direction(struct gpio_chip *chip, unsigned int pin)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
        u32 u;

        regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset, &u);

        if (u & BIT(pin))
                return GPIO_LINE_DIRECTION_IN;

        return GPIO_LINE_DIRECTION_OUT;
}

static int mvebu_gpio_to_irq(struct gpio_chip *chip, unsigned int pin)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);

        return irq_create_mapping(mvchip->domain, pin);
}

/*
 * Functions implementing the irq_chip methods
 */
static void mvebu_gpio_irq_ack(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        u32 mask = d->mask;

        irq_gc_lock(gc);
        mvebu_gpio_write_edge_cause(mvchip, ~mask);
        irq_gc_unlock(gc);
}

static void mvebu_gpio_edge_irq_mask(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        struct irq_chip_type *ct = irq_data_get_chip_type(d);
        u32 mask = d->mask;

        irq_gc_lock(gc);
        ct->mask_cache_priv &= ~mask;
        mvebu_gpio_write_edge_mask(mvchip, ct->mask_cache_priv);
        irq_gc_unlock(gc);
}

static void mvebu_gpio_edge_irq_unmask(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        struct irq_chip_type *ct = irq_data_get_chip_type(d);
        u32 mask = d->mask;

        irq_gc_lock(gc);
        mvebu_gpio_write_edge_cause(mvchip, ~mask);
        ct->mask_cache_priv |= mask;
        mvebu_gpio_write_edge_mask(mvchip, ct->mask_cache_priv);
        irq_gc_unlock(gc);
}

static void mvebu_gpio_level_irq_mask(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        struct irq_chip_type *ct = irq_data_get_chip_type(d);
        u32 mask = d->mask;

        irq_gc_lock(gc);
        ct->mask_cache_priv &= ~mask;
        mvebu_gpio_write_level_mask(mvchip, ct->mask_cache_priv);
        irq_gc_unlock(gc);
}

static void mvebu_gpio_level_irq_unmask(struct irq_data *d)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        struct irq_chip_type *ct = irq_data_get_chip_type(d);
        u32 mask = d->mask;

        irq_gc_lock(gc);
        ct->mask_cache_priv |= mask;
        mvebu_gpio_write_level_mask(mvchip, ct->mask_cache_priv);
        irq_gc_unlock(gc);
}

/*****************************************************************************
 * MVEBU GPIO IRQ
 *
 * GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
 * value of the line or the opposite value.
 *
 * Level IRQ handlers: DATA_IN is used directly as cause register.
 *                     Interrupt are masked by LEVEL_MASK registers.
 * Edge IRQ handlers:  Change in DATA_IN are latched in EDGE_CAUSE.
 *                     Interrupt are masked by EDGE_MASK registers.
 * Both-edge handlers: Similar to regular Edge handlers, but also swaps
 *                     the polarity to catch the next line transaction.
 *                     This is a race condition that might not perfectly
 *                     work on some use cases.
 *
 * Every eight GPIO lines are grouped (OR'ed) before going up to main
 * cause register.
 *
 *                    EDGE  cause    mask
 *        data-in   /--------| |-----| |----\
 *     -----| |-----                         ---- to main cause reg
 *           X      \----------------| |----/
 *        polarity    LEVEL          mask
 *
 ****************************************************************************/

static int mvebu_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
        struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
        struct irq_chip_type *ct = irq_data_get_chip_type(d);
        struct mvebu_gpio_chip *mvchip = gc->private;
        int pin;
        u32 u;

        pin = d->hwirq;

        regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset, &u);
        if ((u & BIT(pin)) == 0)
                return -EINVAL;

        type &= IRQ_TYPE_SENSE_MASK;
        if (type == IRQ_TYPE_NONE)
                return -EINVAL;

        /* Check if we need to change chip and handler */
        if (!(ct->type & type))
                if (irq_setup_alt_chip(d, type))
                        return -EINVAL;

        /*
         * Configure interrupt polarity.
         */
        switch (type) {
        case IRQ_TYPE_EDGE_RISING:
        case IRQ_TYPE_LEVEL_HIGH:
                regmap_update_bits(mvchip->regs,
                                   GPIO_IN_POL_OFF + mvchip->offset,
                                   BIT(pin), 0);
                break;
        case IRQ_TYPE_EDGE_FALLING:
        case IRQ_TYPE_LEVEL_LOW:
                regmap_update_bits(mvchip->regs,
                                   GPIO_IN_POL_OFF + mvchip->offset,
                                   BIT(pin), BIT(pin));
                break;
        case IRQ_TYPE_EDGE_BOTH: {
                u32 data_in, in_pol, val;

                regmap_read(mvchip->regs,
                            GPIO_IN_POL_OFF + mvchip->offset, &in_pol);
                regmap_read(mvchip->regs,
                            GPIO_DATA_IN_OFF + mvchip->offset, &data_in);

                /*
                 * set initial polarity based on current input level
                 */
                if ((data_in ^ in_pol) & BIT(pin))
                        val = BIT(pin); /* falling */
                else
                        val = 0; /* raising */

                regmap_update_bits(mvchip->regs,
                                   GPIO_IN_POL_OFF + mvchip->offset,
                                   BIT(pin), val);
                break;
        }
        }
        return 0;
}

static void mvebu_gpio_irq_handler(struct irq_desc *desc)
{
        struct mvebu_gpio_chip *mvchip = irq_desc_get_handler_data(desc);
        struct irq_chip *chip = irq_desc_get_chip(desc);
        u32 cause, type, data_in, level_mask, edge_cause, edge_mask;
        int i;

        if (mvchip == NULL)
                return;

        chained_irq_enter(chip, desc);

        regmap_read(mvchip->regs, GPIO_DATA_IN_OFF + mvchip->offset, &data_in);
        level_mask = mvebu_gpio_read_level_mask(mvchip);
        edge_cause = mvebu_gpio_read_edge_cause(mvchip);
        edge_mask  = mvebu_gpio_read_edge_mask(mvchip);

        cause = (data_in & level_mask) | (edge_cause & edge_mask);

        for (i = 0; i < mvchip->chip.ngpio; i++) {
                int irq;

                irq = irq_find_mapping(mvchip->domain, i);

                if (!(cause & BIT(i)))
                        continue;

                type = irq_get_trigger_type(irq);
                if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
                        /* Swap polarity (race with GPIO line) */
                        u32 polarity;

                        regmap_read(mvchip->regs,
                                    GPIO_IN_POL_OFF + mvchip->offset,
                                    &polarity);
                        polarity ^= BIT(i);
                        regmap_write(mvchip->regs,
                                     GPIO_IN_POL_OFF + mvchip->offset,
                                     polarity);
                }

                generic_handle_irq(irq);
        }

        chained_irq_exit(chip, desc);
}

static const struct regmap_config mvebu_gpio_regmap_config = {
        .reg_bits = 32,
        .reg_stride = 4,
        .val_bits = 32,
        .fast_io = true,
};

/*
 * Functions implementing the pwm_chip methods
 */
static struct mvebu_pwm *to_mvebu_pwm(struct pwm_chip *chip)
{
        return container_of(chip, struct mvebu_pwm, chip);
}

static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
        struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
        struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
        struct gpio_desc *desc;
        unsigned long flags;
        int ret = 0;

        spin_lock_irqsave(&mvpwm->lock, flags);

        if (mvpwm->gpiod) {
                ret = -EBUSY;
        } else {
                desc = gpiochip_request_own_desc(&mvchip->chip,
                                                 pwm->hwpwm, "mvebu-pwm",
                                                 GPIO_ACTIVE_HIGH,
                                                 GPIOD_OUT_LOW);
                if (IS_ERR(desc)) {
                        ret = PTR_ERR(desc);
                        goto out;
                }

                mvpwm->gpiod = desc;
        }
out:
        spin_unlock_irqrestore(&mvpwm->lock, flags);
        return ret;
}

static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
        struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
        unsigned long flags;

        spin_lock_irqsave(&mvpwm->lock, flags);
        gpiochip_free_own_desc(mvpwm->gpiod);
        mvpwm->gpiod = NULL;
        spin_unlock_irqrestore(&mvpwm->lock, flags);
}

static void mvebu_pwm_get_state(struct pwm_chip *chip,
                                struct pwm_device *pwm,
                                struct pwm_state *state) {

        struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
        struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
        unsigned long long val;
        unsigned long flags;
        u32 u;

        spin_lock_irqsave(&mvpwm->lock, flags);

        regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
        /* Hardware treats zero as 2^32. See mvebu_pwm_apply(). */
        if (u > 0)
                val = u;
        else
                val = UINT_MAX + 1ULL;
        state->duty_cycle = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC,
                        mvpwm->clk_rate);

        regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
        /* period = on + off duration */
        if (u > 0)
                val += u;
        else
                val += UINT_MAX + 1ULL;
        state->period = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC, mvpwm->clk_rate);

        regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u);
        if (u)
                state->enabled = true;
        else
                state->enabled = false;

        spin_unlock_irqrestore(&mvpwm->lock, flags);
}

static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
                           const struct pwm_state *state)
{
        struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
        struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
        unsigned long long val;
        unsigned long flags;
        unsigned int on, off;

        val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
        do_div(val, NSEC_PER_SEC);
        if (val > UINT_MAX + 1ULL)
                return -EINVAL;
        /*
         * Zero on/off values don't work as expected. Experimentation shows
         * that zero value is treated as 2^32. This behavior is not documented.
         */
        if (val == UINT_MAX + 1ULL)
                on = 0;
        else if (val)
                on = val;
        else
                on = 1;

        val = (unsigned long long) mvpwm->clk_rate * state->period;
        do_div(val, NSEC_PER_SEC);
        val -= on;
        if (val > UINT_MAX + 1ULL)
                return -EINVAL;
        if (val == UINT_MAX + 1ULL)
                off = 0;
        else if (val)
                off = val;
        else
                off = 1;

        spin_lock_irqsave(&mvpwm->lock, flags);

        regmap_write(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), on);
        regmap_write(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), off);
        if (state->enabled)
                mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 1);
        else
                mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 0);

        spin_unlock_irqrestore(&mvpwm->lock, flags);

        return 0;
}

static const struct pwm_ops mvebu_pwm_ops = {
        .request = mvebu_pwm_request,
        .free = mvebu_pwm_free,
        .get_state = mvebu_pwm_get_state,
        .apply = mvebu_pwm_apply,
        .owner = THIS_MODULE,
};

static void __maybe_unused mvebu_pwm_suspend(struct mvebu_gpio_chip *mvchip)
{
        struct mvebu_pwm *mvpwm = mvchip->mvpwm;

        regmap_read(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
                    &mvpwm->blink_select);
        regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm),
                    &mvpwm->blink_on_duration);
        regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm),
                    &mvpwm->blink_off_duration);
}

static void __maybe_unused mvebu_pwm_resume(struct mvebu_gpio_chip *mvchip)
{
        struct mvebu_pwm *mvpwm = mvchip->mvpwm;

        regmap_write(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
                     mvpwm->blink_select);
        regmap_write(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm),
                     mvpwm->blink_on_duration);
        regmap_write(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm),
                     mvpwm->blink_off_duration);
}

static int mvebu_pwm_probe(struct platform_device *pdev,
                           struct mvebu_gpio_chip *mvchip,
                           int id)
{
        struct device *dev = &pdev->dev;
        struct mvebu_pwm *mvpwm;
        void __iomem *base;
        u32 offset;
        u32 set;

        if (of_device_is_compatible(mvchip->chip.of_node,
                                    "marvell,armada-370-gpio")) {
                /*
                 * There are only two sets of PWM configuration registers for
                 * all the GPIO lines on those SoCs which this driver reserves
                 * for the first two GPIO chips. So if the resource is missing
                 * we can't treat it as an error.
                 */
                if (!platform_get_resource_byname(pdev, IORESOURCE_MEM, "pwm"))
                        return 0;
                offset = 0;
        } else if (mvchip->soc_variant == MVEBU_GPIO_SOC_VARIANT_A8K) {
                int ret = of_property_read_u32(dev->of_node,
                                               "marvell,pwm-offset", &offset);
                if (ret < 0)
                        return 0;
        } else {
                return 0;
        }

        if (IS_ERR(mvchip->clk))
                return PTR_ERR(mvchip->clk);

        mvpwm = devm_kzalloc(dev, sizeof(struct mvebu_pwm), GFP_KERNEL);
        if (!mvpwm)
                return -ENOMEM;
        mvchip->mvpwm = mvpwm;
        mvpwm->mvchip = mvchip;
        mvpwm->offset = offset;

        if (mvchip->soc_variant == MVEBU_GPIO_SOC_VARIANT_A8K) {
                mvpwm->regs = mvchip->regs;

                switch (mvchip->offset) {
                case AP80X_GPIO0_OFF_A8K:
                case CP11X_GPIO0_OFF_A8K:
                        /* Blink counter A */
                        set = 0;
                        break;
                case CP11X_GPIO1_OFF_A8K:
                        /* Blink counter B */
                        set = U32_MAX;
                        mvpwm->offset += PWM_BLINK_COUNTER_B_OFF;
                        break;
                default:
                        return -EINVAL;
                }
        } else {
                base = devm_platform_ioremap_resource_byname(pdev, "pwm");
                if (IS_ERR(base))
                        return PTR_ERR(base);

                mvpwm->regs = devm_regmap_init_mmio(&pdev->dev, base,
                                                    &mvebu_gpio_regmap_config);
                if (IS_ERR(mvpwm->regs))
                        return PTR_ERR(mvpwm->regs);

                /*
                 * Use set A for lines of GPIO chip with id 0, B for GPIO chip
                 * with id 1. Don't allow further GPIO chips to be used for PWM.
                 */
                if (id == 0)
                        set = 0;
                else if (id == 1)
                        set = U32_MAX;
                else
                        return -EINVAL;
        }

        regmap_write(mvchip->regs,
                     GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset, set);

        mvpwm->clk_rate = clk_get_rate(mvchip->clk);
        if (!mvpwm->clk_rate) {
                dev_err(dev, "failed to get clock rate\n");
                return -EINVAL;
        }

        mvpwm->chip.dev = dev;
        mvpwm->chip.ops = &mvebu_pwm_ops;
        mvpwm->chip.npwm = mvchip->chip.ngpio;
        /*
         * There may already be some PWM allocated, so we can't force
         * mvpwm->chip.base to a fixed point like mvchip->chip.base.
         * So, we let pwmchip_add() do the numbering and take the next free
         * region.
         */
        mvpwm->chip.base = -1;

        spin_lock_init(&mvpwm->lock);

        return pwmchip_add(&mvpwm->chip);
}

#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>

static void mvebu_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
        struct mvebu_gpio_chip *mvchip = gpiochip_get_data(chip);
        u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
        const char *label;
        int i;

        regmap_read(mvchip->regs, GPIO_OUT_OFF + mvchip->offset, &out);
        regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset, &io_conf);
        regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &blink);
        regmap_read(mvchip->regs, GPIO_IN_POL_OFF + mvchip->offset, &in_pol);
        regmap_read(mvchip->regs, GPIO_DATA_IN_OFF + mvchip->offset, &data_in);
        cause   = mvebu_gpio_read_edge_cause(mvchip);
        edg_msk = mvebu_gpio_read_edge_mask(mvchip);
        lvl_msk = mvebu_gpio_read_level_mask(mvchip);

        for_each_requested_gpio(chip, i, label) {
                u32 msk;
                bool is_out;

                msk = BIT(i);
                is_out = !(io_conf & msk);

                seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);

                if (is_out) {
                        seq_printf(s, " out %s %s\n",
                                   out & msk ? "hi" : "lo",
                                   blink & msk ? "(blink )" : "");
                        continue;
                }

                seq_printf(s, " in  %s (act %s) - IRQ",
                           (data_in ^ in_pol) & msk  ? "hi" : "lo",
                           in_pol & msk ? "lo" : "hi");
                if (!((edg_msk | lvl_msk) & msk)) {
                        seq_puts(s, " disabled\n");
                        continue;
                }
                if (edg_msk & msk)
                        seq_puts(s, " edge ");
                if (lvl_msk & msk)
                        seq_puts(s, " level");
                seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear  ");
        }
}
#else
#define mvebu_gpio_dbg_show NULL
#endif

static const struct of_device_id mvebu_gpio_of_match[] = {
        {
                .compatible = "marvell,orion-gpio",
                .data       = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
        },
        {
                .compatible = "marvell,mv78200-gpio",
                .data       = (void *) MVEBU_GPIO_SOC_VARIANT_MV78200,
        },
        {
                .compatible = "marvell,armadaxp-gpio",
                .data       = (void *) MVEBU_GPIO_SOC_VARIANT_ARMADAXP,
        },
        {
                .compatible = "marvell,armada-370-gpio",
                .data       = (void *) MVEBU_GPIO_SOC_VARIANT_ORION,
        },
        {
                .compatible = "marvell,armada-8k-gpio",
                .data       = (void *) MVEBU_GPIO_SOC_VARIANT_A8K,
        },
        {
                /* sentinel */
        },
};

static int mvebu_gpio_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct mvebu_gpio_chip *mvchip = platform_get_drvdata(pdev);
        int i;

        regmap_read(mvchip->regs, GPIO_OUT_OFF + mvchip->offset,
                    &mvchip->out_reg);
        regmap_read(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset,
                    &mvchip->io_conf_reg);
        regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset,
                    &mvchip->blink_en_reg);
        regmap_read(mvchip->regs, GPIO_IN_POL_OFF + mvchip->offset,
                    &mvchip->in_pol_reg);

        switch (mvchip->soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                regmap_read(mvchip->regs, GPIO_EDGE_MASK_OFF + mvchip->offset,
                            &mvchip->edge_mask_regs[0]);
                regmap_read(mvchip->regs, GPIO_LEVEL_MASK_OFF + mvchip->offset,
                            &mvchip->level_mask_regs[0]);
                break;
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
                for (i = 0; i < 2; i++) {
                        regmap_read(mvchip->regs,
                                    GPIO_EDGE_MASK_MV78200_OFF(i),
                                    &mvchip->edge_mask_regs[i]);
                        regmap_read(mvchip->regs,
                                    GPIO_LEVEL_MASK_MV78200_OFF(i),
                                    &mvchip->level_mask_regs[i]);
                }
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                for (i = 0; i < 4; i++) {
                        regmap_read(mvchip->regs,

                                    GPIO_EDGE_MASK_ARMADAXP_OFF(i),
                                    &mvchip->edge_mask_regs[i]);
                        regmap_read(mvchip->regs,
                                    GPIO_LEVEL_MASK_ARMADAXP_OFF(i),
                                    &mvchip->level_mask_regs[i]);
                }
                break;
        default:
                BUG();
        }

        if (IS_ENABLED(CONFIG_PWM))
                mvebu_pwm_suspend(mvchip);

        return 0;
}

static int mvebu_gpio_resume(struct platform_device *pdev)
{
        struct mvebu_gpio_chip *mvchip = platform_get_drvdata(pdev);
        int i;

        regmap_write(mvchip->regs, GPIO_OUT_OFF + mvchip->offset,
                     mvchip->out_reg);
        regmap_write(mvchip->regs, GPIO_IO_CONF_OFF + mvchip->offset,
                     mvchip->io_conf_reg);
        regmap_write(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset,
                     mvchip->blink_en_reg);
        regmap_write(mvchip->regs, GPIO_IN_POL_OFF + mvchip->offset,
                     mvchip->in_pol_reg);

        switch (mvchip->soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                regmap_write(mvchip->regs, GPIO_EDGE_MASK_OFF + mvchip->offset,
                             mvchip->edge_mask_regs[0]);
                regmap_write(mvchip->regs, GPIO_LEVEL_MASK_OFF + mvchip->offset,
                             mvchip->level_mask_regs[0]);
                break;
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
                for (i = 0; i < 2; i++) {
                        regmap_write(mvchip->regs,
                                     GPIO_EDGE_MASK_MV78200_OFF(i),
                                     mvchip->edge_mask_regs[i]);
                        regmap_write(mvchip->regs,
                                     GPIO_LEVEL_MASK_MV78200_OFF(i),
                                     mvchip->level_mask_regs[i]);
                }
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                for (i = 0; i < 4; i++) {
                        regmap_write(mvchip->regs,
                                     GPIO_EDGE_MASK_ARMADAXP_OFF(i),
                                     mvchip->edge_mask_regs[i]);
                        regmap_write(mvchip->regs,
                                     GPIO_LEVEL_MASK_ARMADAXP_OFF(i),
                                     mvchip->level_mask_regs[i]);
                }
                break;
        default:
                BUG();
        }

        if (IS_ENABLED(CONFIG_PWM))
                mvebu_pwm_resume(mvchip);

        return 0;
}

static int mvebu_gpio_probe_raw(struct platform_device *pdev,
                                struct mvebu_gpio_chip *mvchip)
{
        void __iomem *base;

        base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(base))
                return PTR_ERR(base);

        mvchip->regs = devm_regmap_init_mmio(&pdev->dev, base,
                                             &mvebu_gpio_regmap_config);
        if (IS_ERR(mvchip->regs))
                return PTR_ERR(mvchip->regs);

        /*
         * For the legacy SoCs, the regmap directly maps to the GPIO
         * registers, so no offset is needed.
         */
        mvchip->offset = 0;

        /*
         * The Armada XP has a second range of registers for the
         * per-CPU registers
         */
        if (mvchip->soc_variant == MVEBU_GPIO_SOC_VARIANT_ARMADAXP) {
                base = devm_platform_ioremap_resource(pdev, 1);
                if (IS_ERR(base))
                        return PTR_ERR(base);

                mvchip->percpu_regs =
                        devm_regmap_init_mmio(&pdev->dev, base,
                                              &mvebu_gpio_regmap_config);
                if (IS_ERR(mvchip->percpu_regs))
                        return PTR_ERR(mvchip->percpu_regs);
        }

        return 0;
}

static int mvebu_gpio_probe_syscon(struct platform_device *pdev,
                                   struct mvebu_gpio_chip *mvchip)
{
        mvchip->regs = syscon_node_to_regmap(pdev->dev.parent->of_node);
        if (IS_ERR(mvchip->regs))
                return PTR_ERR(mvchip->regs);

        if (of_property_read_u32(pdev->dev.of_node, "offset", &mvchip->offset))
                return -EINVAL;

        return 0;
}

static int mvebu_gpio_probe(struct platform_device *pdev)
{
        struct mvebu_gpio_chip *mvchip;
        const struct of_device_id *match;
        struct device_node *np = pdev->dev.of_node;
        struct irq_chip_generic *gc;
        struct irq_chip_type *ct;
        unsigned int ngpios;
        bool have_irqs;
        int soc_variant;
        int i, cpu, id;
        int err;

        match = of_match_device(mvebu_gpio_of_match, &pdev->dev);
        if (match)
                soc_variant = (unsigned long) match->data;
        else
                soc_variant = MVEBU_GPIO_SOC_VARIANT_ORION;

        /* Some gpio controllers do not provide irq support */
        err = platform_irq_count(pdev);
        if (err < 0)
                return err;

        have_irqs = err != 0;

        mvchip = devm_kzalloc(&pdev->dev, sizeof(struct mvebu_gpio_chip),
                              GFP_KERNEL);
        if (!mvchip)
                return -ENOMEM;

        platform_set_drvdata(pdev, mvchip);

        if (of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios)) {
                dev_err(&pdev->dev, "Missing ngpios OF property\n");
                return -ENODEV;
        }

        id = of_alias_get_id(pdev->dev.of_node, "gpio");
        if (id < 0) {
                dev_err(&pdev->dev, "Couldn't get OF id\n");
                return id;
        }

        mvchip->clk = devm_clk_get(&pdev->dev, NULL);
        /* Not all SoCs require a clock.*/
        if (!IS_ERR(mvchip->clk))
                clk_prepare_enable(mvchip->clk);

        mvchip->soc_variant = soc_variant;
        mvchip->chip.label = dev_name(&pdev->dev);
        mvchip->chip.parent = &pdev->dev;
        mvchip->chip.request = gpiochip_generic_request;
        mvchip->chip.free = gpiochip_generic_free;
        mvchip->chip.get_direction = mvebu_gpio_get_direction;
        mvchip->chip.direction_input = mvebu_gpio_direction_input;
        mvchip->chip.get = mvebu_gpio_get;
        mvchip->chip.direction_output = mvebu_gpio_direction_output;
        mvchip->chip.set = mvebu_gpio_set;
        if (have_irqs)
                mvchip->chip.to_irq = mvebu_gpio_to_irq;
        mvchip->chip.base = id * MVEBU_MAX_GPIO_PER_BANK;
        mvchip->chip.ngpio = ngpios;
        mvchip->chip.can_sleep = false;
        mvchip->chip.of_node = np;
        mvchip->chip.dbg_show = mvebu_gpio_dbg_show;

        if (soc_variant == MVEBU_GPIO_SOC_VARIANT_A8K)
                err = mvebu_gpio_probe_syscon(pdev, mvchip);
        else
                err = mvebu_gpio_probe_raw(pdev, mvchip);

        if (err)
                return err;

        /*
         * Mask and clear GPIO interrupts.
         */
        switch (soc_variant) {
        case MVEBU_GPIO_SOC_VARIANT_ORION:
        case MVEBU_GPIO_SOC_VARIANT_A8K:
                regmap_write(mvchip->regs,
                             GPIO_EDGE_CAUSE_OFF + mvchip->offset, 0);
                regmap_write(mvchip->regs,
                             GPIO_EDGE_MASK_OFF + mvchip->offset, 0);
                regmap_write(mvchip->regs,
                             GPIO_LEVEL_MASK_OFF + mvchip->offset, 0);
                break;
        case MVEBU_GPIO_SOC_VARIANT_MV78200:
                regmap_write(mvchip->regs, GPIO_EDGE_CAUSE_OFF, 0);
                for (cpu = 0; cpu < 2; cpu++) {
                        regmap_write(mvchip->regs,
                                     GPIO_EDGE_MASK_MV78200_OFF(cpu), 0);
                        regmap_write(mvchip->regs,
                                     GPIO_LEVEL_MASK_MV78200_OFF(cpu), 0);
                }
                break;
        case MVEBU_GPIO_SOC_VARIANT_ARMADAXP:
                regmap_write(mvchip->regs, GPIO_EDGE_CAUSE_OFF, 0);
                regmap_write(mvchip->regs, GPIO_EDGE_MASK_OFF, 0);
                regmap_write(mvchip->regs, GPIO_LEVEL_MASK_OFF, 0);
                for (cpu = 0; cpu < 4; cpu++) {
                        regmap_write(mvchip->percpu_regs,
                                     GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu), 0);
                        regmap_write(mvchip->percpu_regs,
                                     GPIO_EDGE_MASK_ARMADAXP_OFF(cpu), 0);
                        regmap_write(mvchip->percpu_regs,
                                     GPIO_LEVEL_MASK_ARMADAXP_OFF(cpu), 0);
                }
                break;
        default:
                BUG();
        }

        devm_gpiochip_add_data(&pdev->dev, &mvchip->chip, mvchip);

        /* Some MVEBU SoCs have simple PWM support for GPIO lines */
        if (IS_ENABLED(CONFIG_PWM)) {
                err = mvebu_pwm_probe(pdev, mvchip, id);
                if (err)
                        return err;
        }

        /* Some gpio controllers do not provide irq support */
        if (!have_irqs)
                return 0;

        mvchip->domain =
            irq_domain_add_linear(np, ngpios, &irq_generic_chip_ops, NULL);
        if (!mvchip->domain) {
                dev_err(&pdev->dev, "couldn't allocate irq domain %s (DT).\n",
                        mvchip->chip.label);
                err = -ENODEV;
                goto err_pwm;
        }

        err = irq_alloc_domain_generic_chips(
            mvchip->domain, ngpios, 2, np->name, handle_level_irq,
            IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_LEVEL, 0, 0);
        if (err) {
                dev_err(&pdev->dev, "couldn't allocate irq chips %s (DT).\n",
                        mvchip->chip.label);
                goto err_domain;
        }

        /*
         * NOTE: The common accessors cannot be used because of the percpu
         * access to the mask registers
         */
        gc = irq_get_domain_generic_chip(mvchip->domain, 0);
        gc->private = mvchip;
        ct = &gc->chip_types[0];
        ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
        ct->chip.irq_mask = mvebu_gpio_level_irq_mask;
        ct->chip.irq_unmask = mvebu_gpio_level_irq_unmask;
        ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
        ct->chip.name = mvchip->chip.label;

        ct = &gc->chip_types[1];
        ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
        ct->chip.irq_ack = mvebu_gpio_irq_ack;
        ct->chip.irq_mask = mvebu_gpio_edge_irq_mask;
        ct->chip.irq_unmask = mvebu_gpio_edge_irq_unmask;
        ct->chip.irq_set_type = mvebu_gpio_irq_set_type;
        ct->handler = handle_edge_irq;
        ct->chip.name = mvchip->chip.label;

        /*
         * Setup the interrupt handlers. Each chip can have up to 4
         * interrupt handlers, with each handler dealing with 8 GPIO
         * pins.
         */
        for (i = 0; i < 4; i++) {
                int irq = platform_get_irq_optional(pdev, i);

                if (irq < 0)
                        continue;
                irq_set_chained_handler_and_data(irq, mvebu_gpio_irq_handler,
                                                 mvchip);
        }

        return 0;

err_domain:
        irq_domain_remove(mvchip->domain);
err_pwm:
        pwmchip_remove(&mvchip->mvpwm->chip);

        return err;
}

static struct platform_driver mvebu_gpio_driver = {
        .driver         = {
                .name           = "mvebu-gpio",
                .of_match_table = mvebu_gpio_of_match,
        },
        .probe          = mvebu_gpio_probe,
        .suspend        = mvebu_gpio_suspend,
        .resume         = mvebu_gpio_resume,
};
builtin_platform_driver(mvebu_gpio_driver);